<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgpu - shadow map</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>
		<div id="info">
		<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgpu - webgpu shadow map
		</div>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.webgpu.js",
					"three/tsl": "../build/three.webgpu.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';
			import { mx_fractal_noise_vec3, positionWorld, vec4, Fn, color, vertexIndex, hash } from 'three/tsl';

			import { OrbitControls } from 'three/addons/controls/OrbitControls.js';

			let camera, scene, renderer, clock;
			let dirLight, spotLight;
			let torusKnot, dirGroup;

			init();

			function init() {

				camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 1000 );
				camera.position.set( 0, 10, 20 );

				scene = new THREE.Scene();
				scene.backgroundNode = color( 0x222244 );
				scene.fog = new THREE.Fog( 0x222244, 50, 100 );

				// lights

				scene.add( new THREE.AmbientLight( 0x444444, 2 ) );

				spotLight = new THREE.SpotLight( 0xff8888, 400 );
				spotLight.angle = Math.PI / 5;
				spotLight.penumbra = 0.3;
				spotLight.position.set( 8, 10, 5 );
				spotLight.castShadow = true;
				spotLight.shadow.camera.near = 8;
				spotLight.shadow.camera.far = 200;
				spotLight.shadow.mapSize.width = 2048;
				spotLight.shadow.mapSize.height = 2048;
				spotLight.shadow.bias = - 0.002;
				spotLight.shadow.radius = 4;
				scene.add( spotLight );


				dirLight = new THREE.DirectionalLight( 0x8888ff, 3 );
				dirLight.position.set( 3, 12, 17 );
				dirLight.castShadow = true;
				dirLight.shadow.camera.near = 0.1;
				dirLight.shadow.camera.far = 500;
				dirLight.shadow.camera.right = 17;
				dirLight.shadow.camera.left = - 17;
				dirLight.shadow.camera.top	= 17;
				dirLight.shadow.camera.bottom = - 17;
				dirLight.shadow.mapSize.width = 2048;
				dirLight.shadow.mapSize.height = 2048;
				dirLight.shadow.radius = 4;
				dirLight.shadow.bias = - 0.0005;

				dirGroup = new THREE.Group();
				dirGroup.add( dirLight );
				scene.add( dirGroup );

				// geometry

				const geometry = new THREE.TorusKnotGeometry( 25, 8, 75, 80 );
				const material = new THREE.MeshPhongNodeMaterial( {
					color: 0x999999,
					shininess: 0,
					specular: 0x222222
				} );

				const materialCustomShadow = material.clone();
				materialCustomShadow.transparent = true;

				const materialColor = vec4( 1, 0, 1, .5 );
			
				const discardNode = hash( vertexIndex ).greaterThan( 0.5 );

				materialCustomShadow.colorNode = Fn( () => {

					discardNode.discard();

					return materialColor;

				} )();


				materialCustomShadow.shadowNode = Fn( () => {

					discardNode.discard();

					return materialColor;
			
				} )();

				torusKnot = new THREE.Mesh( geometry, materialCustomShadow );
				torusKnot.scale.multiplyScalar( 1 / 18 );
				torusKnot.position.y = 3;
				torusKnot.castShadow = true;
				torusKnot.receiveShadow = true;
				scene.add( torusKnot );

				const cylinderGeometry = new THREE.CylinderGeometry( 0.75, 0.75, 7, 32 );

				const pillar1 = new THREE.Mesh( cylinderGeometry, material );
				pillar1.position.set( 8, 3.5, 8 );
				pillar1.castShadow = true;

				const pillar2 = pillar1.clone();
				pillar2.position.set( 8, 3.5, - 8 );
				const pillar3 = pillar1.clone();
				pillar3.position.set( - 8, 3.5, 8 );
				const pillar4 = pillar1.clone();
				pillar4.position.set( - 8, 3.5, - 8 );

				scene.add( pillar1 );
				scene.add( pillar2 );
				scene.add( pillar3 );
				scene.add( pillar4 );

				const planeGeometry = new THREE.PlaneGeometry( 200, 200 );
				const planeMaterial = new THREE.MeshPhongMaterial( {
					color: 0x999999,
					shininess: 0,
					specular: 0x111111
				} );

				planeMaterial.shadowPositionNode = Fn( () => {

					const pos = positionWorld.toVar();
					pos.xz.addAssign( mx_fractal_noise_vec3( positionWorld.mul( 2 ) ).saturate().xz );
					return pos;

				} )();


				planeMaterial.colorNode = Fn( () => {

					const pos = positionWorld.toVar();
					pos.xz.addAssign( mx_fractal_noise_vec3( positionWorld.mul( 2 ) ).saturate().xz );
					return mx_fractal_noise_vec3( positionWorld.mul( 2 ) ).saturate().zzz.mul( 0.2 ).add( .5 );

				} )();

				const ground = new THREE.Mesh( planeGeometry, planeMaterial );
				ground.rotation.x = - Math.PI / 2;
				ground.scale.multiplyScalar( 3 );
				ground.castShadow = true;
				ground.receiveShadow = true;
				scene.add( ground );

				// renderer

				renderer = new THREE.WebGPURenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setAnimationLoop( animate );
				renderer.toneMapping = THREE.ACESFilmicToneMapping;
				document.body.appendChild( renderer.domElement );

				// Mouse control
				const controls = new OrbitControls( camera, renderer.domElement );
				controls.target.set( 0, 2, 0 );
				controls.minDistance = 7;
				controls.maxDistance = 40;
				controls.update();

				clock = new THREE.Clock();

				window.addEventListener( 'resize', resize );

			}

			function resize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function animate( time ) {

				const delta = clock.getDelta();

				torusKnot.rotation.x += 0.25 * delta;
				torusKnot.rotation.y += 0.5 * delta;
				torusKnot.rotation.z += 1 * delta;

				dirGroup.rotation.y += 0.7 * delta;
				dirLight.position.z = 17 + Math.sin( time * 0.001 ) * 5;

				renderer.render( scene, camera );

			}

		</script>
	</body>
</html>
